Clearance certificate

On the 28Aug i settled my last outstanding creditor. I emailed the proof to debt busters. On the 31Aug i was advised that there is still 4 outstanding paid up letters. It took me a while but i emailed it to debt busters on the 8 sep. On the 16th i got a mail back saying thanks for the letters they will advise on any outstanding letters. So i took it upon myself to email them ALL the paid up letters for every single creditor on review. Then waiting another 6 days on the 22nd they rep**** there is still 3 different outstanding which i have send to them already on the 16th. I emailed those 3 again and called in to complain. The guy i spoke to said he will make sure i get my clearance certificate the same day. I only got a reply saying that the letter was send for indexing and will advise. I asked for a ETA and got no feedback. I want to know when will i get my Clearance certificate. Please note its been a week since they received all paid up letters. Why did they only ask for 4 in the beginning and them after 16day for the other 3. Why not all 7 them at once then this would have been settled already. FEEDBACK PLEASE